New Delhi: The next serological survey to check for the prevalence of antibodies against the novel coronavirus among people will start in Delhi within a fortnight, Health Minister Satyendar Jain said on Thursday.Seroprevalence of antibodies to COVID-19 reduced to 25.1 per cent in September from nearly 29 per cent last month among people in the national capital, the Delhi High Court was informed on Wednesday.These are the findings of the third round of sero survey carried out by the AAP government in the national capital between September 1 and September 7.The first sero survey was conducted by the Delhi government in collaboration with the National Centre for Disease Control (NCDC).The next two surveys were conducted by the Delhi.